Single-mode subwavelength waveguide with channel plasmon-polaritons in triangular grooves on a metal surface

We demonstrate that single-mode operation of a subwavelength plasmonic waveguide in the form of a V-groove on a metal surface can be achieved by adjusting the depth of the groove. Strongly localized channel plasmon-polaritons (CPPs) are shown to propagate in such waveguides. If the groove depth is close to the penetration depth of the fundamental CPP mode, then all higher modes are not supported by the structure, leaving only the fundamental mode propagating in the groove. In this case, propagation distances of fundamental mode similar to10 mum can easily be achieved together with strong subwavelength localization. (C) 2004 American Institute of Physics.